Because the selling price will be more than your Adjusted Basis, you use the Adjusted Basis ($190,000 purchase, plus cost of improvements, minus the $30,000 of depreciation) to calculate the gain. So it looks like you have roughly a $80,000 Gain ($30,000 of depreciation, plus $50,000 of long-term capital gain).
If the selling price was less than your Adjusted Basis, it gets a bit more complicated. However, that doesn't apply to you.
TurboTax incorrectly guides you for reporting this sale. When you sell the "asset" in the rental section and you get to the "Special Handling" screen, you need to say YES. Then you report the sale in the Sale of Business Property section, using your Adjusted Basis.
